Light coupled detachable stern anchor and navigation light for boats

ABSTRACT

An apparatus and method that improves the usable life and reliability of detachable stem lights for boats. It replaces electrical energy coupling by light energy coupling, thereby eliminating electrical contact corrosion problems.

This application claims priority of provisional application 60/950,650 filed on 19 Jul. 2007.

REFERENCES SITED

US Patent Documents 4,389,085 June 1983 Mori 4,740,870 April 1988 Moore 5,161,874 November 1992 Benes 5,339,225 August 1994 Wiggerman 6,155,195 December 2000 Nirenberg 6,742.916 B1 June 2004 Dunn

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to boat stern lights for anchor and navigational purposes. Specifically, to detachable (stowable) stem lights, which allow the light to be stored out of the way, an advantage for many daytime activities and boat storage.

2. Background

Detachable (sometimes called stowable) stem lights typically consist of a base which is mounted to the boat structure and a pole which mechanically couples to the base. The pole has a light emitting device (typically an incandescent bulb) at the distal end. Power to energize the bulb is coupled via electrical contacts at the base and the proximal end of the pole.

Electrical contacts are composed primarily of copper and copper alloys. Although weather covers are typically provided to cover the base electrical contacts, water intrusion almost always occurs. Copper electrical contacts exposed to moisture leads to corrosion and eventual electrical failure of the contacts. The problem is particularly acute in marine environments.

Several U.S. patents describe prior art systems which are related but differ from the invention.

U.S. Pat. No. 4,389,085 to Mori describes a fiber optic system which collects and distributes sunlight.

U.S. Pat. No. 4,740,870 to Moore discloses a central light source which is transmitted to different areas of a boat via fiber optic cabling.

U.S. Pat. No. 5,161,874 to Benes describes a remote illumination system that utilizes a single light source and a light pipe to transmit the light to some remote locations from the source.

U.S. Pat. No. 5,339,225 to Wiggerman is a boat stern light design that illuminates the length of the pole, as opposed to just having a light at the distal end.

U.S. Pat. No. 6,155,195 to Nirenberg discloses a telescoping stern light that can be retracted out of the way when not in use.

U.S. Pat. No. 6,742,916 B1 to Dunn describes a fiber optic cabling system for the sides of boats which is intended illuminate said side for safety or enjoyment purposes.

SUMMARY OF THE INVENTION

Previous detachable stern light designs utilize electrical contacts between the base and detachable pole. The contacts connect the electrical power present in the base component to wires within the pole, which in turn transmit the electrical power to a distal end mounted light bulb.

The invention eliminates the electrical contacts corrosion problem of previous designs by transmitting light instead of electrical current across the coupling of the base and pole. It further replaces the combined pole and light bulb assembly into a single light conduit (pole).

In the broadest form, the invention consists of a boat, a base mounted to the boat, a external electrical power connection, a electrical power conditioning device, an optical source, a detachable optical conduit (pole) that mounts to the base, and a mechanism to redirect and emit the transmitted light out of the optical conduit.

The boat is any vessel that is required to have or desires to have a detachable stern light.

The base is essentially a boat mounted socket for the pole. The socket provides mechanical mounting and light (not electrical) coupling between the base and light conduit (pole). In various embodiments, the base may have the optical source incorporated into it or the optical source may be externally mounted to it.

The optical source may be formed by a multitude of visible light emitting devices, in one embodiment being a high intensity LED or LEDs.

The electrical power may be from any suitable source which can energize the optical source. In one embodiment, the source is the boat's electrical power system.

The electrical power conditioning circuit can consists of any device capable of converting the incoming electrical power to a form required by the optical source. Examples of such devices range from a simple power resistor to switching power topology circuits.

The optical conduit may also take a multitude of embodiments, one being an acrylic rod. A key characteristic of the optical conduit is the efficient conduction of light. The diameter and length of the optical conduit is determined by the application. The rod may or may not have an external opaque covering.

The redirection mechanism for the light traveling within the light conduit may also take multiple forms. A fundamental characteristic of the mechanism is reflection of the conduit light to a direction which causes it to be emitted in essentially perpendicular (or nearly so) directions to the light conduit (pole). This emission may be in a 360 degree pattern or some lesser or subset(s) of 360 degrees around the boat.

In the following section, one embodiment of the invention is explained in detail. The invention is not intended to be limited in its application to the details of construction and to the arrangements of the components described in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways.

Also, the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.

It is the intention of the invention to provide a new detachable marine anchor and navigational stern light system which overcomes the disadvantages of previous systems which is not anticipated, rendered obvious, suggested, or even implied by any of the prior art boat light systems, either alone or in any combination.

BRIEF DESCRIPTION OF THE DRAWINGS

The following drawings illustrate the best modes presently contemplated for carrying out the present invention (Preferred Embodiment):

FIG. 1 Perspective component view of the invention and how they interface.

FIG. 2 Cross Section View of Invention with detail

DESCRIPTION OF THE PREFERRED EMBODIMENT

Principle of Operation

The basic principle is that a light conduit (pole) couples the light source contained in the base to an apparatus at the top of the light conduit that disperses the light so as to meet the requirements of boat stem lights determined by the USCG and/or other regulatory agencies.

Refer to FIGS. 1 and 2 for the following description.

The Components:

The preferred embodiment consists of two primary components: base 4 mounted to the boat structure 5 and an acrylic light conduit 2 (shown detached), which plugs into the base light conduit socket 3.

The base contains an encapsulated LED light source 12 and LED drive device 9 where said LED light is directed upward into the optical conduit socket 3. The encapsulated LED is located at the bottom end of the light conduit socket 3 so as to minimize physical separation between the LED and the installed optical conduit.

The optical conduit socket 3 diameter is such as to provide a slip fit to the optical conduit, thus providing secure attachment of the optical conduit, yet still allowing it to be easily removed.

Electrical wires are provided on the lower side of the base to connect to the boat electrical power system or separate electrical power source.

The base 4 may be constructed of any material suitable for the marine environment. Examples include aluminum, stainless steel and a variety of plastics and composites. This preferred embodiment utilizes aluminum.

The optical conduit 2 is constructed from a clear acrylic rod. The diameter is not critical and is primarily determined by the proximal end surface area needed to couple the optical source light radiation pattern. Another diameter consideration is structural integrity, larger diameters being sturdier. This preferred embodiment uses a one inch diameter acrylic rod.

The length of the optical conduit 2 is likewise not critical, and can be varied to meet the height requirements of the application. The primary limitation on length is light intensity loss, however that can be offset by higher optical source intensity as needed. The preferred embodiment uses a length of thirty six inches. The dimensions chosen for the preferred embodiment are not intended to be a limitation in any sense, since the length and diameter of the acrylic rod can be of nearly arbitrary length, as needed by the application.

The acrylic optical conduit has a cone 1 machined into the distal end to form a light redirection surface. The maximum diameter of the cone is sized so as to nearly match the diameter of the acrylic rod, tapering down to a point at the center of the acrylic rod. The cone angle of the preferred embodiment is sixty degrees.

Description of Operation

Electrical Section

The base 4, on its lower side, provides wires or terminals 6 for connection to the boat electrical power system. Alternatively, a battery or other electrical power source separate from the boat electrical system may be used. The base 4 contains the LED light source 12 that is directed upward inside the base socket so as to project light into the mating optical conduit. The LED light source is a state-of-the-art high intensity white LED available from multiple semiconductor manufacturers. The invention anticipates continuing advancements in LED technology which will provide more light output for less power consumption, hence improving overall efficiency and enabling longer optical conduit lengths.

The LED is driven by the LED drive device 9 which conditions the voltage presented via the electrical connection 6 to the drive requirements of the LED. The LED drive device can take the form of a simple voltage dropping power resistor or a switching power supply design for lower power dissipation and more accurate LED current control. Multiple semiconductor manufactures provide LED driver circuits which are switching power supply topology based designs. For most application the switching power supply design is preferred due to its low power dissipation and more accurate LED current control. The voltage dropping resistor is suitable to applications were the input voltage will not result in excessive power dissipation.

The LED light source 12 and the LED drive device 9 are epoxy encapsulated within the base to prevent water damage.

Optical Section

The light emerging from the LED light source 12 is optically coupled into the removable light conduit installed into the base socket. The light conduit 2 in this preferred embodiment is constructed from an acrylic rod which has excellent light transmission properties. The light inside the conduit experiences nearly total internal reflection, maximizing optical power transmission.

An optional opaque outer covering 11 further increases the internal reflection and blocks light from emerging along the periphery of the light conduit.

The distal end of the rod has a cone machined into it forming a reflective surface 7, due to the optical discontinuity. The light traveling within the light conduit 8 is reflected by the cone's reflective surface 7 and is emitted 10 at angles largely perpendicular to the light conduit. Since light impinges essentially the entire reflective surface 7 of the cone, the light is emitted in a three hundred sixty degree pattern around the light conduit.

The emitted light pattern can be reduced or segmented via opaque coverings over the sections where light is not desired to be emitted. 

1) A marine stern light system for a boat, comprising: a base mounted to or within a boat structure to which a removable optical conduit mounts; a connection to an electrical power source; a means to convert the supplied electrical power to a form required by the optical source; an optical source, as part of the base, which converts electrical power to light and projects said light into the removable optical conduit, when said optical conduit is installed; a detachable optical conduit (pole) of application appropriate diameter, which has a proximal end which fits securely in the base, but is easily removed from the base, a middle portion of a length required by the application, that when installed, conducts the base optical source light within itself, and a mechanism to redirect and emit the light conducted within the optical conduit out of the distal end. 2) The marine stem light system described in claim 1, where a boat is any vessel that is required to display a stem light for navigational or anchorage purposes, as determined by applicable regulations. 3) The marine stem light system described in claim 1, where a boat is any vessel that elects to display a stem light. 4) The marine stem light system described in claim 1, where the base serves as a mechanical mounting socket for the light conduit (pole) and provides light coupling between the optical source and the light conduit. 5) The marine stem light system described in claim 1, where the base is mounted to or within the stern area of the boat, as required by applicable regulations. 6) The marine stem light system described in claim 1, where the base is mounted to any superstructure of the boat that a stem or navigation light is permitted by applicable regulations. 7) The marine stem light system described in claim 1, where the base is mounted to or within an outboard engine covering. 8) The marine stern light system described in claim 1, where the device to condition the incoming electrical power is a voltage dropping power resistor. 9) The marine stern light system described in claim 1, where the device to condition the incoming electrical power is a switching power supply topology based circuit. 10) The marine stern light system described in claim 1, where the optical source is a Light Emitting Diode (LED) or LEDs. 11) The marine stern light system described in claim 1, where the optical source is an incandescent lamp or lamps. 12) The marine stern light system described in claim 1, where the optical source is a fluorescent lamp or lamps. 13) The marine stern light system described in claim 1, where the optical source is a LASER or LASERs. 14) The marine stern light system described in claim 1, where the optical source may have any wavelength or wavelengths in the visible spectrum. 15) The optical source described in claim 14, where the optical source wavelengths produce a white or variant of white color. 16) The marine stern light system described in claim 1, where the optical source receives its electrical power from the boat electrical system. 17) The marine stern light system described in claim 1, where the optical source receives its electrical power from a source independent of the boat electrical system. 18) The marine stern light system described in claim 1, where the optical source is integral to and sealed within the base. 19) The marine stern light system described in claim 1, where the optical source is separate from and attached to the base. 20) The marine stern light system described in claim 1, where the optical conduit consists of an optically transmissive rod, rods, fiber or fibers. 21) The optical conduit of claim 20, where the rods or fibers are made from plastics such as acrylic and polycarbonate, or glass. 22) The marine stern light system described in claim 1, where the optical conduit outer surface consists of a material opaque to light. 23) The optical conduit of claim 22, where said outer surface consists of aluminum, copper, steel, opaque plastics or opaque coatings. 24) The marine stern light system described in claim 1, where the optical conduit outer surface consist of a material opaque to light and the interior of the optical conduit consists of the optically transmissive rod, rods, fiber or fibers 25) The marine stern light system described in claim 1, where the interior of the optical conduit is gas filled. 26) The marine stern light system described in claim 1, where the interior of the optical conduit is a partial or complete vacuum. 27) The marine stern light system described in claim 1, where the optical conduit light is redirected and emitted via an optically reflective surface at the distal end. 28) The marine stern light system described in claim 1, where the light reflection and redirection at the distal end of the light conduit is from an optical discontinuity at the distal end of the optical conduit. 29) The light redirection and emitting via reflection described in claim 28, where said optical discontinuity is formed by machining a conical shaped hole into the distal end. 30) The marine stern light system described in claim 1, where the light reflection and redirection at the distal end of the light conduit is from an apparatus attached to the distal end of the optical conduit. 31) The light redirection and emitting via reflection described in claim 30, where the light leaving the optical conduit encounters a cone shaped reflector in the air and is emitted. 32) The light redirection and emitting via reflection described in claim 30, with a light diffuser cover. 33) The marine stern light system described in claim 1, where the light emerging from the distal end of the optical conduit may be emitted in up to a 360 degree pattern, or a segmented pattern around the boat. 34) The light emission pattern described in claim 33, where the light pattern is formed by selectively placing coverings opaque to light over the areas where light transmission is not desired. 35) The marine stern light system described in claim 1, where the length and diameter of the optical conduit may be of any suitable dimensions consistent with the requirements of its intended use. 36) The optical conduit length and diameter described in claim 35, where the diameter is one inch and the length may be from one inch to forty eight inches. 